Generally speaking, each integrated circuit (IC) could provide multiple operation modes. These operation modes of the integrated circuit are always completed configured during the power on or button reset, so as to ensure the correct operation mode of the integrated circuit to be operating. Because the configurations are to be determined during power on period, it is hard to use the software or firmware manner to adjust. In the conventional integrated circuit design, the pins used for executing configuration could only be used to receive the configuration signal during configuration setting of integrated circuit, and could not provide for application of other functions. Thus, when the operation modes of integrated circuit are increased, the pins of integrated circuit would be increased accordingly in response to the design of operation mode. Therefore, how to reduce the number of pins required for setting the configuration of integrated circuit would still be the targets of development by the engineers. The related techniques and research could be referred to U.S. Pat. No. 6,831,479 B2, and R.O.C. Patent Publication No. 200633381, and the like.